Oral administration of Salinomycin to pigs

ABSTRACT

Agents containing Salinomycin for oral administration to domestic animals which do not digest cellulose in the rumen, particularly pigs, are disclosed, for instance for the prophylactic treatment of disease and/or for improvement of growth.

This is a continuation of application Ser. No. 790,602, filed Apr. 25,1977 and now abandoned.

The present invention relates to an agent to be administered orally todomestic animals which do not have a cellulose digestion in the rumen.

The present invention also relates to the use of Salinomycin fordomestic animals not having a cellulose digestion in the rumen,especially pigs, for the prophylaxis and therapy of disturbances in thegastro-intestinal tract by bacterial infections, and also to obtain animproved growth as well as an improved nutrient efficiency. It providesfurther the agents containing Salinomycin to be administered orally tothese animals, as well as a process for their preparation.

Gastro-intestinal infections play an important part in domestic animalsand especially in young animals, such as piglets, and lead toconsiderable economic losses. Alterations of the gastro-intestinal floracaused by a change of feed, but also specific bacterial germs, areetiologically important and lead clinically to diarrhea diseases. Anespecially feared disease, which involves heavy losses, is the dysenteryof pigs caused by Treponema hyodysenteriae.

For many years, numerous antibiotics and chemotherapeutical agents havebeen used for the prophylaxis and therapy of these gastro-intestinalinfections, of which there are to be mentioned, above all,tetracyclines, aminoglycoside antibiotics, macrolide antibiotics,nitrofurans, 5-nitro-imidazoles, and acridines. The success has in manycases been unsatisfactory, since resistant strains of germs haveincreasingly appeared and Treponema hyodysenteriae above all is not, ornot to a sufficient degree, influenced by the known therapeutic agents.

It has now been found that Salinomycin shows a particularly good effectagainst dysentery infections in domestic animals without cellulosedigestion in the rumen, that it has a greater influence on the germ ofthe dysentery of pigs than the preparations used so far, and, moreover,that it shows a remarkable growth-stimulating effect.

As physiologically acceptable salts and esters to be used according tothe invention instead of, or together with, Salinomycin, there are used,for example, alkali metal salts, especially the sodium, potassium orammonium salts, alkaline earth metal salts, particularly the magnesiumor calcium salts, and alkyl esters, especially those having from 1 to 8,preferably from 1 to 4 carbon atoms, as well as benzylester.

As domestic animals not having a cellulose digestion in the rumen thereare considered preferably agricultural livestock, in particular mammals,preferably pigs.

Salinomycin, its salts and esters have been described, for example inBritish Pat. No. 1,378,413 and in German Offenlegungsschrift No. 2 353998. In these places, its use as anticoccidiosis agent has also beenmentioned.

In "The Journal of Antibiotics" XXVII, 11, 814-821 (1974), theantibacterial spectrum of activity and the action intensity ofSalinomycin have also been described, inter alia, in which case only aninsignificant or moderate effect against the specified microorganismshas been found.

The particular effectiveness of the said substance in the prophylaxisand therapy of gastro-intestinal infections in domestic animals withoutcellulose digestion in the rumen, the excellent effect on Treponemahyodysenteriae, the germ of the dysentery of pigs, and also thegrowth-stimulating effect in domestic animals without a rumen digestionwere therefore surprising and could not have been foreseen.

In order to detect the surprising effect on Treponema hyodysenteriae,this microorganism was cultivated according to the method of Harris on atrypticase-soy-agar using an addition of horse blood of 5% in a CO₂ /H₂atmosphere, and the minimum inhibiting concentration of Salinomycin wasdetermined in the agar diffusion test, while using the correspondingdilution series, as compared against commercial preparations showing aparticularly good effect in dysentery diseases.

Table 1 shows the superior effect of Salinomycin.

                  TABLE 1                                                         ______________________________________                                                           Minimum inhibiting con-                                                       centration                                                                    (MIC) in mcg/ml                                            ______________________________________                                        Tetracycline-HCl     50                                                       Oxytetracycline      100                                                      Erythromycin         >100                                                     Tylosin              >100                                                     3,6-Diamino-10-methyl-acridinium                                                                   100                                                      chloride                                                                      Ethacridine lactate  100                                                      Dimethridazol        5                                                        Ipronidazol          2                                                        Salinomycin          0.05                                                     ______________________________________                                    

According to the invention, Salinomycin may be administered as the puresubstance, as a raw product, or as a mycelium.

For commercial reasons it may be advantageous not to use the puresubstance, but the mycelium, especially in the case of an addition tothe feed.

It is possible to add the agents used according to the invention, forexample, to the supplementary feed or to the all-mash feed, or only topart of the daily feed ration. Generally, an addition to the mixed feedwill be preferred.

A preferred method of administering the active substance is in manycases its addition to the feed in the form of a concentrate (premix).The concentrate may be prepared, for example, by mixing the activesubstance, the raw product or the mycelium containing the activesubstance with a physiologically acceptable solid or liquid carrier. Assolid carriers there may be mentioned, for example, by-products ofcereals, such as wheat flour of inferior quality, wheat bran or de-oiledrice bran, but also corn meal, soy meal, bolus alba or calciumcarbonate. As liquid carriers, there may be used physiological saltsolutions, distilled water and physiologically acceptable organicsolvents. It is also possible to add suitable additives, such asemulsifying agents, dispersing agents, wetting agents or gelatinizingagents. These concentrates may contain as a rule from about 0.5 to about5% of the active substance, however the concentration of this substancemay also be considerably higher or lower, depending on the purpose ofapplication.

For administering the active substances together with feeding stuffs, aconcentrate is suitably mixed with the feed by grinding, shaking,stirring. The use of a powdery concentrate has proved to be particularlyuseful for being mixed with feed.

Another method of administering the active substance consists in addingsaid substance as such or in the form of a concentrate or suspendablepowder to the drinking water or another drink, for example, milkreplacer.

The feed to which the active substance is to be added in accordance withthe invention comprises the common feeding stuffs, for example, cereals,such as corn, wheat, barley, oats as well as soy meal, other oilseedmeals, fish meal and mixed feed prepared from the above ingredients,supplementary feed or mixtures of mineral substances.

The mixing with the feed may also be effected in a way that a substanceof the invention is administered directly orally to the animals before,during or after feeding, for example in the form of a solid or liquidgalenic preparation, such as a tablet, a capsule, a paste, granules, apowder, a bolus, a juice or syrup, or in the form of a concentratementioned above. In this way the mixing with the feed--which isimportant according to the invention--is effected immediately after theapplication in the stomach, thus producing the effect of a considerablyimproved nutrient efficiency and an increased growth according to theinvention in the same manner.

Especially in the case of a controlled diarrhea treatment orprophylaxis, the administration in the form of such galenic preparationscan be of particular interest.

For the administration in the form of tablets, capsules, pastes, boli,pills, granules, juices, syrups, etc., the same auxiliary agents andadditives may be added, as are commonly known for galenic preparationsfrom pharmaceutical technology. The active substances may be mixed, forexample, with powdery diluents, such as microcrystalline cellulose,sugar or starch for filling up the volume of the capsule. Thepreparation of the tablets may also be performed in common manner, whileadding substances, for example, cellulose, lactose, sodium chloride,starch, surface-active agents, such as sodium laurylsulfate, bindingagents, such as gelatin, starch, dextrin, cellulose derivatives, etc.For the preparation of liquid formulations, use may also be made of theauxiliary agents which are common in pharmacy, such as vegetable oils,collidone, cellulose derivatives, inter alia auxiliary dispersing agentsor emulsifying agents, water, etc. An aqueous suspension of Salinomycinmay for example contain, besides Salinomycin, raw product or groundmycelium, carboxymethyl cellulose, collidone 25, Aerosil, appropriatebuffer substances, and water.

Combinations with other antibiotics and chemotherapeutical agents, suchas, for example, sulfonamides, nitrofurans, quinoxaline-N-oxides,5-nitro-imidazoles, tetracyclines, aminoglycoside and macrolideantibiotics, Flavomycin and/or Virginiamycin or arsenicals are alsopossible, especially for the broadening of the spectrum of activity.

Depending on the indication and the kind of application, the dosage maybe in the range of from about 0.02 to about 5.0, preferably from about0.2 to about 2.0 mg of the active substance used according to theinvention per kg of body weight and day. This results in a concentrationin the feed of from about 0.5 to 500, preferably from about 2 to 100 gof active substance per ton.

Depending on the animal species and the age of the animals, galenicpreparations may contain, for example, from about 4 to 400, preferablyfrom about 10 to 100 mg of active substance per dosage unit, by whichunit there is to be understood, for example, a tablet, a capsule, abolus, etc.; concentrates (premixes) may contain, for example,concentrations in the range of from about 0.1 to 10%, preferably fromabout 1 to 5% of active substance. The above-mentioned dosage limits mayeasily be exceeded in appropriate cases.

The following Examples serve to illustrate the invention.

EXAMPLE 1

A feeding test using Salinomycin was carried out on 78 piglets whichwere kept in boxes with 4 (or 3) animals each. At the beginning of thetest, the animals were about 4 weeks old. Four replicates formed onegroup, and the following treatments were carried out:

1st group: untreated control group

2nd group: Salinomycin as raw product: 25 mg/kg of fodder

3rd group: Salinomycin as raw product: 50 mg/kg of fodder

4th group: Salinomycin as mycelium: 50 mg/kg of fodder

5th group: comparison preparation A: 50 mg/kg of fodder (5-Nitromidazol)

The basic feed had the following composition:

    ______________________________________                                        Fish meal              5%                                                     coarse meal of linseed cake                                                                          5%                                                     coarse meal of soybean 25%                                                    coarse meal of barley  50%                                                    wheat bran             11%                                                    CaCO.sub.3             2%                                                     Na-Mg-Ca-phosphate     1%                                                     NaCl                   0.6%                                                   mixture of trace elements                                                                            0.2%                                                   vitamin premix         0.2%                                                                          100%                                                   Total nutrients        660                                                    Digestible protein     19.2%                                                  ______________________________________                                    

The occurrence of diarrhea in the individual boxes (sub-groups) wasregistered in the test periods of 14 days each and in the total test runof 56 days. Table 2 shows the "diarrhea days" of each test group inabsolute figures and as percent of the respective test days. Of a totalof 224 test days, for example, the control animals showed diarrhea on185 days (=82.6%), whereas the test group using 50 mg of Salinomycin (asmycelium) per kg of feed showed diarrhea only on 24 days (=10.7%).Salinomycin was found to have a very good influence on the incidence ofdiarrhea depending on the dosage, as compared against the untreatedcontrol and a comparison preparation.

EXAMPLE 2

A feeding test using Salinomycin as a raw product was carried out on 46piglets weaned at an early age (4 weeks old) that were kept insub-groups comprising 3 or 4 animals.

Initial weight: 9.8 kg on an average. The feed ration indicated inExample 1 served as basic feed.

4 Sub-groups comprising 15 animals altogether formed the untreatedcontrol group. 4 Sub-groups comprising 16 animals altogether were given25 mg of Salinomycin as raw product per kg of feed, and 4 sub-groupscomprising 15 animals altogether were given 50 mg of Salinomycin per kgof feed in the form of the raw product. The test period was 8 weeks,with individual weighing at intervals of 2 weeks.

Results:

Table 3 shows as a comparison the weight gain and the feed efficiency inthe control group and the test groups. The improvement obtained by 25 mgof Salinomycin per kg of feed could be covered statistically with asignificance of 99%, and the improvement obtained by 50 mg ofSalinomycin per kg of feed was shown even with a significance of 99.9%.

                                      TABLE 2                                     __________________________________________________________________________    Piglet test S 83/75 for examining the incidence of diarrhea                   4 Stalls with 14 test days = 56 days per test period (= 100%)                 4 Test periods with 56 days = 224 days altogether (= 100%)                                       Incidence of diarrhea in test days and/or percent          Group.   Stall                                                                            No. of 1st and                                                                            3rd and                                                                            5th and                                                                           7th and                                                                           1st through                              No.      No.                                                                              animals                                                                              2nd week                                                                           4th week                                                                           6th wk.                                                                           8th wk.                                                                           8th week                                 __________________________________________________________________________    Control   1 15  days                                                                             33   49   54  49  185/224                                           12                                                                            25                                                                            34     %  58.9 87.5 96.4                                                                              87.5                                                                              82.6                                     Salinomycin raw                                                                         2     days                                                                             27   26   39  43  135/224                                           11                                                                   pr. dos. 25 ppm                                                                        24 16                                                                         35     %  48.2 46.6 69.6                                                                              76.8                                                                              60.3                                     Salinomycin raw                                                                         3     days                                                                             7    7    16  13  43/224                                            14                                                                   pr. dos. 50 ppm                                                                        21 15                                                                         36     %  12.5 12.5 28.6                                                                              23.2                                                                              19.1                                     Salinomycin as                                                                          4                                                                   mycelium, 10%                                                                          13                                                                   activity 26 16  days                                                                             11   3    4   6   24/224                                   dos. 50 ppm                                                                            31     %  19.6 5.4  7.1 10.7                                                                              10.7                                     Prep. A (5-Nitro-                                                                       6     days                                                                             20   22   41  39  122/224                                  imidazol)                                                                              15 16                                                                         22                                                                   dos. 50 ppm                                                                            23     %  35.7 39.3 73.2                                                                              69.6                                                                              54.5                                     __________________________________________________________________________

                  TABLE 3                                                         ______________________________________                                        Effect of Salinomycin (as raw product) on the growth                          and the feed efficiency in piglets weaned early                               (4 weeks old)                                                                           Control                                                                       initial  Salinomycin  Salinomycin                                             weight   25 ppm       50 ppm                                                  9.8 kg   init. wt. 9.8 kg                                                                           init. wt. 9.8 kg                              Test      n = 15   n = 16       n = 15                                        weeks     absolute abs.    rel.   abs. rel.                                   ______________________________________                                        Weight                                                                              2        2.3      2.4  104.3%  2.4 104.3%                               gain  4        6.7      7.0  104.6   7.2 107.5                                per   6       12.6     13.0  103.3  13.8 109.8                                animal                                                                              8       20.5     21.3  103.8.sup.++                                                                         22.2 108.2.sup.+++                        in kg                                                                         Daily 2       164      171   --     171  --                                   weight                                                                              4       239      250   --     257  --                                   gain p.                                                                             6       307      317   --     337  --                                   animal                                                                              8       366      380   --     396  --                                   in g                                                                          Feed  2       1.983    1.900 95.8%  1.900                                                                              95.8%                                effi- 4       1.881    1.800 95.7   1.750                                                                              93.0                                 ciency                                                                              6       1.860    1.802 96.9   1.698                                                                              91.3                                 per   8       1.972    1.898 96.2.sup.++                                                                          1.821                                                                              92.3.sup.+++                         animal                                                                        ______________________________________                                         .sup.++ = 99% significance                                                    .sup.+++ = 99.9% significance                                            

EXAMPLE 3

A feeding test using Salinomycin as a mycelium was carried out on 47piglets weaned at an early age (4 weeks old) which were kept insub-groups comprising 4 and 3 animals, respectively. The initial weightwas 9.8 kg on an average. The feed ration indicated in Example 1 servedas basic feed.

4 Sub-groups comprising 15 animals altogether formed the untreatedcontrol group. 4 Sub-groups comprising 16 animals altogether were given50 mg of Salinomycin as a mycelium per kg of feed, and 4 sub-groupscomprising 16 animals altogether were given 50 mg of a comparisonpreparation A (5-Nitroimidazol) per kg of feed. The test period was 8weeks, with individual weighing at intervals of 2 weeks.

Results:

Table 4 shows as a comparison the weight gain and the feed efficiency inthe individual groups. The improvement of the weight developmentobtained by 50 mg of Salinomycin per kg of feed could be coveredstatistically with a significance of 99.9% after a test period of 8weeks, and the improvement of the feed efficiency with a significance of99%. In contradistinction thereto, the effect of the comparisonpreparation could not be covered.

                  TABLE 4                                                         ______________________________________                                        Effect of Salinomycin (as mycelium) on the growth                             and the feed efficiency in piglets weaned early                               (4 weeks old)                                                                            Control  Salinomycin                                                          initial wt.                                                                            50 ppm       Preparation A                                           9.8 kg   init. wt. 9.8 kg                                                                           50 ppm                                       Test       n = 15   n = 16       n = 16                                       weeks      absolute abs.   rel.    abs.  rel.                                 ______________________________________                                        Weight 2        2.3      2.3 100.0%   2.5  109.1%                             gain   4        6.7      7.3 109.2    7.0  104.6                              p. ani-                                                                              6       12.6     13.6 108.1   13.2  104.9                              mal in 8       20.5     22.0 107.4.sup.+++                                                                         20.9  101.9                              kg                                                                            Daily  2       164      164  --      179   --                                 weight 4       239      261  --      250   --                                 gain   6       307      332  --      322   --                                 p. ani-                                                                              8       366      393  --      373   --                                 mal                                                                           in g                                                                          Feed   2       1.983    1.983                                                                              100.0%  1.824 92.0%                              efficien-                                                                            4       1.881    1.726                                                                              91.8    1.800 95.7                               cy     6       1.860    1.723                                                                              92.6    1.775 95.4                               p. ani-                                                                              8       1.972    1.837                                                                              93.2.sup.++                                                                           1.934 98.1                               mal                                                                           ______________________________________                                         .sup. ++  = 99% significance                                                  .sup.+++  = 99.9% significance                                           

What is claimed is:
 1. The method for improving the growth and nutrient efficiency of pigs free of swine dysentery, which method comprises orally administering thereto an effective amount of an active agent selected from the group consisting of Salinomycin, physiologically acceptable salts thereof, and physiologically acceptable esters thereof.
 2. The method as in claim 1 wherein from about 0.02 mg to 5.0 mg of said active agent is administered per day per kg of body weight.
 3. The method as in claim 1 wherein said active agent is administered in combination with a feeding substance.
 4. The method as in claim 3 wherein said active agent is presented in said feeding substance in a concentration from 0.5 g to 500 g per ton.
 5. The method as in claim 1 wherein said active agent is administered in combination with a supplemental feed.
 6. The method as in claim 5 wherein said active agent is present in a concentrate at a concentration from about 0.1 percent to 10 percent.
 7. The method as in claim 1 wherein said active agent is administered in combination with a pharmaceutical auxiliary.
 8. The method as in claim 7 wherein said active agent is present with said pharmaceutical auxiliary in an amount from about 4 mg to 400 mg per dosage unit form.
 9. The method as in claim 1 wherein Salinomycin is administered as a salt or ester thereof, or as a mixture of a salt and ester thereof.
 10. The method as in claim 1 wherein Salinomycin is administered as an alkali metal or alkaline earth metal salt thereof.
 11. The method as in claim 1 wherein Salinomycin is administered as its sodium, potassium, ammonium, magnesium, or calcium salt.
 12. The method as in claim 1 wherein Salinomycin is administered as a C₁ -C₂ alkyl ester or as the benzyl ester thereof.
 13. The method as in claim 1 wherein Salinomycin is administered as mycelium or raw product.
 14. The method as in claim 1 wherein said active agent is administered in drinking water, some other drink, or in a liquid feeding substance. 